Trace mineral deficiencies in rats caused by feeding rapeseed flours during growth, gestation and lactation
Anderson, G.H.; Harris, L.; Rao, A.V.; Jones, J.D.
Journal of Nutrition 106(8): 1166-1174
1976
ISSN/ISBN: 0022-3166 PMID: 939997 Document Number: 98391
The present study determined the effect of duration of feeding and dietary levels of rapeseed [Brassica napus] flours on growth, outcome of gestation and lactation and blood trace element content of rats. In the first 2 experiments, female rats were fed either casein or rapeseed flour diets during gestation and lactation, or prior to and during gestation. In the last 2 experiments, weanling male rats were fed either casein or rapeseed flour diets with or without added Zn for 4 wk. Feeding rapeseed flours prior to and/or during gestation caused a reduction in weight of the pups born. Plasma Zn levels were low in the mother rats at parturition and plasma Zn and Fe levels were low in weanling rats after 4 wk of feeding the rapeseed diets. Adding 300 ppm Zn to the diet prevented the decrease in food consumption, weight gains and plasma Zn levels in the weanling rats. The recommended levels of trace elements in the rat diet are inadequate for the purpose of bioassay and toxicological evaluation of rapeseed preparations. In order that the nutritional potential of new protein sources be correctly evaluated, guidelines for adequacy of mineral in such diets should be determined. [The toxic effects of rapeseed flour have previously been attributed to its high content of phytic acid, leading to a Zn deficiency during gestation.].